Previously, many types of cable grips or grabs have been used in endeavoring to provide an effective means for tightening a wire rope cable to a fixed position and allowing removal or loosening of the cable. This use is particularly adaptable for horizontal lifeline applications.
The prior art listed below did not disclose any patents that possess the novelty of the instant invention, however the following U.S. patents are considered related:
Pat. No.InventorIssue Date4,114,242LuthiSep. 19, 19785,677,975Burek et al.Oct. 13, 19975,924,522OstrobrodJul. 20, 19996,446,936OstrobrodSep. 10, 20026,581,725ChoateJun. 24, 2003
U.S. Pat. No. 4,114,242 issued to Luthi discloses a cable grip or gripping apparatus that uses tapered segmented grips to de-tension a tensioned member. The apparatus consists of a body with slotted gripping means having similar tensioning members gripping a cable. The gripping means are in coaxial configuration with the tensioning members.
U.S. Pat. No. 5,677,975 issued to Burek et al. discloses a grip block assembly having a hollow frame with wall openings that allow an elongated member to pass therethrough. Lever arms pivot on the same axis as a cable functions in a scissoring manner to grip the cable surface. An actuator block has depending members which contact the lever arms, thus causing them to pivot with respect to each other.
U.S. Pat. No. 5,924,522 issued to Ostrobrod discloses a cable grab which has a frame assembly with a U-shaped bracket and a pair of spaced-apart side plates which fit around the cable. A secondary frame fits within the U-shaped bracket and carries a brake in the form of a pulley mounted in an elongated slot that locks in the event of a fall.
U.S. Pat. No. 6,446,936 issued to Ostrobrod discloses a lifeline safety apparatus consisting of housing secured to an anchor point. The free end of the lifeline is connected to a cable passing around a drum, and an adjustable lever winds the drum. When tension on the lifeline reaches a desired level a brake slips and the lever rotates freely.
U.S. Pat. No. 6,581,725 issued to Choate discloses a method for creating a horizontal lifeline between two anchorages. A section of the lifeline has a modulus of elasticity, thereby providing shock absorbing capabilities and is tuned to equal the deployment load.